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-rw-r--r--hw/char/cadence_uart.c153
1 files changed, 87 insertions, 66 deletions
diff --git a/hw/char/cadence_uart.c b/hw/char/cadence_uart.c
index f18db53bca..1012f1ad64 100644
--- a/hw/char/cadence_uart.c
+++ b/hw/char/cadence_uart.c
@@ -34,6 +34,9 @@
#define UART_SR_INTR_RFUL 0x00000004
#define UART_SR_INTR_TEMPTY 0x00000008
#define UART_SR_INTR_TFUL 0x00000010
+/* somewhat awkwardly, TTRIG is misaligned between SR and ISR */
+#define UART_SR_TTRIG 0x00002000
+#define UART_INTR_TTRIG 0x00000400
/* bits fields in CSR that correlate to CISR. If any of these bits are set in
* SR, then the same bit in CISR is set high too */
#define UART_SR_TO_CISR_MASK 0x0000001F
@@ -43,6 +46,7 @@
#define UART_INTR_PARE 0x00000080
#define UART_INTR_TIMEOUT 0x00000100
#define UART_INTR_DMSI 0x00000200
+#define UART_INTR_TOVR 0x00001000
#define UART_SR_RACTIVE 0x00000400
#define UART_SR_TACTIVE 0x00000800
@@ -110,23 +114,37 @@
#define CADENCE_UART(obj) OBJECT_CHECK(UartState, (obj), TYPE_CADENCE_UART)
typedef struct {
+ /*< private >*/
SysBusDevice parent_obj;
+ /*< public >*/
MemoryRegion iomem;
uint32_t r[R_MAX];
- uint8_t r_fifo[RX_FIFO_SIZE];
+ uint8_t rx_fifo[RX_FIFO_SIZE];
+ uint8_t tx_fifo[TX_FIFO_SIZE];
uint32_t rx_wpos;
uint32_t rx_count;
+ uint32_t tx_count;
uint64_t char_tx_time;
CharDriverState *chr;
qemu_irq irq;
QEMUTimer *fifo_trigger_handle;
- QEMUTimer *tx_time_handle;
} UartState;
static void uart_update_status(UartState *s)
{
+ s->r[R_SR] = 0;
+
+ s->r[R_SR] |= s->rx_count == RX_FIFO_SIZE ? UART_SR_INTR_RFUL : 0;
+ s->r[R_SR] |= !s->rx_count ? UART_SR_INTR_REMPTY : 0;
+ s->r[R_SR] |= s->rx_count >= s->r[R_RTRIG] ? UART_SR_INTR_RTRIG : 0;
+
+ s->r[R_SR] |= s->tx_count == TX_FIFO_SIZE ? UART_SR_INTR_TFUL : 0;
+ s->r[R_SR] |= !s->tx_count ? UART_SR_INTR_TEMPTY : 0;
+ s->r[R_SR] |= s->tx_count >= s->r[R_TTRIG] ? UART_SR_TTRIG : 0;
+
s->r[R_CISR] |= s->r[R_SR] & UART_SR_TO_CISR_MASK;
+ s->r[R_CISR] |= s->r[R_SR] & UART_SR_TTRIG ? UART_INTR_TTRIG : 0;
qemu_set_irq(s->irq, !!(s->r[R_IMR] & s->r[R_CISR]));
}
@@ -139,24 +157,6 @@ static void fifo_trigger_update(void *opaque)
uart_update_status(s);
}
-static void uart_tx_redo(UartState *s)
-{
- uint64_t new_tx_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
-
- timer_mod(s->tx_time_handle, new_tx_time + s->char_tx_time);
-
- s->r[R_SR] |= UART_SR_INTR_TEMPTY;
-
- uart_update_status(s);
-}
-
-static void uart_tx_write(void *opaque)
-{
- UartState *s = (UartState *)opaque;
-
- uart_tx_redo(s);
-}
-
static void uart_rx_reset(UartState *s)
{
s->rx_wpos = 0;
@@ -164,15 +164,11 @@ static void uart_rx_reset(UartState *s)
if (s->chr) {
qemu_chr_accept_input(s->chr);
}
-
- s->r[R_SR] |= UART_SR_INTR_REMPTY;
- s->r[R_SR] &= ~UART_SR_INTR_RFUL;
}
static void uart_tx_reset(UartState *s)
{
- s->r[R_SR] |= UART_SR_INTR_TEMPTY;
- s->r[R_SR] &= ~UART_SR_INTR_TFUL;
+ s->tx_count = 0;
}
static void uart_send_breaks(UartState *s)
@@ -237,8 +233,16 @@ static void uart_parameters_setup(UartState *s)
static int uart_can_receive(void *opaque)
{
UartState *s = (UartState *)opaque;
+ int ret = MAX(RX_FIFO_SIZE, TX_FIFO_SIZE);
+ uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE;
- return RX_FIFO_SIZE - s->rx_count;
+ if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) {
+ ret = MIN(ret, RX_FIFO_SIZE - s->rx_count);
+ }
+ if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) {
+ ret = MIN(ret, TX_FIFO_SIZE - s->tx_count);
+ }
+ return ret;
}
static void uart_ctrl_update(UartState *s)
@@ -253,10 +257,6 @@ static void uart_ctrl_update(UartState *s)
s->r[R_CR] &= ~(UART_CR_TXRST | UART_CR_RXRST);
- if ((s->r[R_CR] & UART_CR_TX_EN) && !(s->r[R_CR] & UART_CR_TX_DIS)) {
- uart_tx_redo(s);
- }
-
if (s->r[R_CR] & UART_CR_STARTBRK && !(s->r[R_CR] & UART_CR_STOPBRK)) {
uart_send_breaks(s);
}
@@ -272,24 +272,13 @@ static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size)
return;
}
- s->r[R_SR] &= ~UART_SR_INTR_REMPTY;
-
if (s->rx_count == RX_FIFO_SIZE) {
s->r[R_CISR] |= UART_INTR_ROVR;
} else {
for (i = 0; i < size; i++) {
- s->r_fifo[s->rx_wpos] = buf[i];
+ s->rx_fifo[s->rx_wpos] = buf[i];
s->rx_wpos = (s->rx_wpos + 1) % RX_FIFO_SIZE;
s->rx_count++;
-
- if (s->rx_count == RX_FIFO_SIZE) {
- s->r[R_SR] |= UART_SR_INTR_RFUL;
- break;
- }
-
- if (s->rx_count >= s->r[R_RTRIG]) {
- s->r[R_SR] |= UART_SR_INTR_RTRIG;
- }
}
timer_mod(s->fifo_trigger_handle, new_rx_time +
(s->char_tx_time * 4));
@@ -297,13 +286,55 @@ static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size)
uart_update_status(s);
}
+static gboolean cadence_uart_xmit(GIOChannel *chan, GIOCondition cond,
+ void *opaque)
+{
+ UartState *s = opaque;
+ int ret;
+
+ /* instant drain the fifo when there's no back-end */
+ if (!s->chr) {
+ s->tx_count = 0;
+ }
+
+ if (!s->tx_count) {
+ return FALSE;
+ }
+
+ ret = qemu_chr_fe_write(s->chr, s->tx_fifo, s->tx_count);
+ s->tx_count -= ret;
+ memmove(s->tx_fifo, s->tx_fifo + ret, s->tx_count);
+
+ if (s->tx_count) {
+ int r = qemu_chr_fe_add_watch(s->chr, G_IO_OUT, cadence_uart_xmit, s);
+ assert(r);
+ }
+
+ uart_update_status(s);
+ return FALSE;
+}
+
static void uart_write_tx_fifo(UartState *s, const uint8_t *buf, int size)
{
if ((s->r[R_CR] & UART_CR_TX_DIS) || !(s->r[R_CR] & UART_CR_TX_EN)) {
return;
}
- qemu_chr_fe_write_all(s->chr, buf, size);
+ if (size > TX_FIFO_SIZE - s->tx_count) {
+ size = TX_FIFO_SIZE - s->tx_count;
+ /*
+ * This can only be a guest error via a bad tx fifo register push,
+ * as can_receive() should stop remote loop and echo modes ever getting
+ * us to here.
+ */
+ qemu_log_mask(LOG_GUEST_ERROR, "cadence_uart: TxFIFO overflow");
+ s->r[R_CISR] |= UART_INTR_ROVR;
+ }
+
+ memcpy(s->tx_fifo + s->tx_count, buf, size);
+ s->tx_count += size;
+
+ cadence_uart_xmit(NULL, G_IO_OUT, s);
}
static void uart_receive(void *opaque, const uint8_t *buf, int size)
@@ -337,26 +368,17 @@ static void uart_read_rx_fifo(UartState *s, uint32_t *c)
return;
}
- s->r[R_SR] &= ~UART_SR_INTR_RFUL;
-
if (s->rx_count) {
uint32_t rx_rpos =
(RX_FIFO_SIZE + s->rx_wpos - s->rx_count) % RX_FIFO_SIZE;
- *c = s->r_fifo[rx_rpos];
+ *c = s->rx_fifo[rx_rpos];
s->rx_count--;
- if (!s->rx_count) {
- s->r[R_SR] |= UART_SR_INTR_REMPTY;
- }
qemu_chr_accept_input(s->chr);
} else {
*c = 0;
- s->r[R_SR] |= UART_SR_INTR_REMPTY;
}
- if (s->rx_count < s->r[R_RTRIG]) {
- s->r[R_SR] &= ~UART_SR_INTR_RTRIG;
- }
uart_update_status(s);
}
@@ -401,6 +423,7 @@ static void uart_write(void *opaque, hwaddr offset,
uart_parameters_setup(s);
break;
}
+ uart_update_status(s);
}
static uint64_t uart_read(void *opaque, hwaddr offset,
@@ -428,8 +451,10 @@ static const MemoryRegionOps uart_ops = {
.endianness = DEVICE_NATIVE_ENDIAN,
};
-static void cadence_uart_reset(UartState *s)
+static void cadence_uart_reset(DeviceState *dev)
{
+ UartState *s = CADENCE_UART(dev);
+
s->r[R_CR] = 0x00000128;
s->r[R_IMR] = 0;
s->r[R_CISR] = 0;
@@ -440,8 +465,7 @@ static void cadence_uart_reset(UartState *s)
uart_rx_reset(s);
uart_tx_reset(s);
- s->rx_count = 0;
- s->rx_wpos = 0;
+ uart_update_status(s);
}
static int cadence_uart_init(SysBusDevice *dev)
@@ -455,15 +479,10 @@ static int cadence_uart_init(SysBusDevice *dev)
s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL,
(QEMUTimerCB *)fifo_trigger_update, s);
- s->tx_time_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL,
- (QEMUTimerCB *)uart_tx_write, s);
-
s->char_tx_time = (get_ticks_per_sec() / 9600) * 10;
s->chr = qemu_char_get_next_serial();
- cadence_uart_reset(s);
-
if (s->chr) {
qemu_chr_add_handlers(s->chr, uart_can_receive, uart_receive,
uart_event, s);
@@ -483,17 +502,18 @@ static int cadence_uart_post_load(void *opaque, int version_id)
static const VMStateDescription vmstate_cadence_uart = {
.name = "cadence_uart",
- .version_id = 1,
- .minimum_version_id = 1,
- .minimum_version_id_old = 1,
+ .version_id = 2,
+ .minimum_version_id = 2,
+ .minimum_version_id_old = 2,
.post_load = cadence_uart_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT32_ARRAY(r, UartState, R_MAX),
- VMSTATE_UINT8_ARRAY(r_fifo, UartState, RX_FIFO_SIZE),
+ VMSTATE_UINT8_ARRAY(rx_fifo, UartState, RX_FIFO_SIZE),
+ VMSTATE_UINT8_ARRAY(tx_fifo, UartState, RX_FIFO_SIZE),
VMSTATE_UINT32(rx_count, UartState),
+ VMSTATE_UINT32(tx_count, UartState),
VMSTATE_UINT32(rx_wpos, UartState),
VMSTATE_TIMER(fifo_trigger_handle, UartState),
- VMSTATE_TIMER(tx_time_handle, UartState),
VMSTATE_END_OF_LIST()
}
};
@@ -505,6 +525,7 @@ static void cadence_uart_class_init(ObjectClass *klass, void *data)
sdc->init = cadence_uart_init;
dc->vmsd = &vmstate_cadence_uart;
+ dc->reset = cadence_uart_reset;
}
static const TypeInfo cadence_uart_info = {
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-10 05:28:10 +0000